Double belt sander



1946- D. DOHERTY DOUBLE BELT SANDER 4 Sheets-Sheet 1 Filed June 8, 1944 Inventor [JAN/4 00/1512 7'),

D. DOHERTY Nov. 12, 1946.

DOUBLE BELT SANDER 4 Sheets-Sheet 2 Filed June 8, 1944 A. WW

NOV. 12, 1946. DOHERTY DOUBLE BELT SANDER Filed June 8, 1944 4 Sheets-Sheet 5 Inventor B, QM

/ Aftomqys Nov. 12, 1946.- D. DOHER TY 2,411,085

DOUBLE BELT SANDER Filed Jun 8, 1944 4 Sheets-Sheet 4 Inventor Patented Nov. 12, 1946 DOUBLE BELT SANDER Daniel Doherty, Los Angeles, Calif. Application June 8, 1944, Serial No. 539,247

7 Claims.

This invention relates to a double belt wet sander which is expressly, but not necessarily, adapted for properly and accurately sanding plastic blocks and the purpose of the invention is to provide a feasible and practicable motor driven parallel belt assemblage susceptible of achieving desired aims with reliability and expediency.

In carrying out the principles of the invention I provide a suitable frame structure, this to accomrriodate motor-driven upper and lower parallel belts, there being means for bodily moving the belts toward and from each other in parallelism and an arrangement between the adjacent flights of the belts to accommodate an especially constructed work holder which deploys the work in effective sanding relation to said belts. u

Another phase of the invention has to do with spray nozzles for spraying jets of water against the ends of the belts, this for purposes of keeping said belts sufficiently wet and moist to achieve the desired abrading and surfacing results.

Novelty is also predicated upon the adoption and use of a collection receptacle underneath the belts, this to trap the water and to thereafter drain it off as conditions require.

Additional novelty has to do with the provision and use of a vertically or perpendicularly adjustable shelf, this to accommodate the work while it is being taken out of the work holder and also to assist in placing the work in said holder before the holder is slid in between the active flights of said belts.

. Further novelty is predicated upon the provision of a specially constructed work holder, this being a simple clamp such as expedites insertion and removal of the work.

Other features and advantages will become more readily apparent from the following description and the accompanying illustrative drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

Figure 1 is a side elevational view of a twin belt wet sander constructed in accordance with the principles of the instant invention.

Figures 2 and 3 are horizontal longitudinal sectional views taken approximately on the planes of the lines 2-2 and 3-3, respectively, of Figure 1, looking downwardly in the direction of the arrows.

Figure 4 is a central vertical section.

igure 5 is a perspective View of the clampingtype work holder.

Referring now to the drawings by distinguishing reference numerals it will be seen that the main frame structure comprises suitable supporting legs 6 and vertical end panels or uprights l and horizontal connecting rails 8 at the top, the latter being sufficiently open to permit access to be had to the upper portion of the structure.

The upper and lower belt assemblies are denoted by the numerals 9 and I0, respectively. Each is the same in construction and the description of one will suffice for both. Reference being had to the upper unit or assemblage 9, this comprises a substantially U-shaped frame having a longitudinal connective or bight portion H and transverse ends [2. The end members are protided with feed nuts [3 through which the vertical feed screws [4 extend. These feed screws are properly mounted and the upper ends extend above the frame structure and are provided with beveled gears 15 coacting with beveled gears IE on the ends of the horizontal adjusting shaft 17. This shaft is provided at its center with beveled pinions l3 coacting with an associated pinion I9 on the shaft of the hand wheel 29. As seen in Figure 4 this hand wheel and shaft is mounted for operation in an appropriate fixture or bracket 2!. Thus, the frames which accommodate the units 9 and I!) are adjusted up and down in parallelism. The threads on the feed shafts or screws M are oppositely arranged to accomplish this method of moving the units 9 and Ill toward and from each other.

At the left (see Figure 3) the frame is provided with a lateral arm 22 terminating in an adapter 23 having a bearing to accommodate the shaft 24 of the drum 25. At the opposite end I provide a fixed yoke 26 which serves to support the relatively slidable yoke 21, the latter serving as a hanger for the right hand drum 28. The yoke 27 is adjusted by the set screws 29 to thus tauten the endless sanding belt 3!} the latter trained over said pulleys. that appropriate parallel platens 3| serve to properly sustain and support the upper and lower flights of the belt.

As seen in Figure 1, each belt is provided with a water supply nozzle or pipe 32 fed by an appropriately controlled delivery or supply hose 33. The jets face the belt and the water is controlled to wet or moisten the belt to the desired degree.

The shafts and the belts are provided with appropriate pulleys 34 to accommodate motion transmitting belts 35 which, in turn, connect with pulleys 36 on the shaft of themotor 31. This motor is supported on aplatform 38 having an adjusting slot 39 to permit movement of the motor In Figure 1 it will be seen units and other parts.

3 toward and from the main frame structure. The part 49 is a stabilizing link for the motor.

As seen in Figure 4, 4! denotes a receptacle or pan which is located at the bottom of the frame structure and underlies the belt assemblage to trap the water. This has a suitable drain 42. Also, at the front it is provided with a chute 43 which traps water which drips from the work holder and returns the same to the main part of the receptacle.

I direct attention again to Figure 4, where it will be seen that the aforementioned work-accommodation shelf is indicated at 44, this being I mounted on the shaft 45 adjustably held in place by a set-screw arrangement 46.

Coming now to the work holder reference is had to Figure 5 where it will be seen that this is de-, I

noted as a unit by the numeral 41. able frame and includes end members 48 which slide in guideways 49 on the track rails 50. The work holder also includes an abutment 5| and a spring-pressed clamping bar 52, this being pressed in place against the work 53 by coiled springs 54. A T-shaped handle arrangement is provided and the stem 55 is connected with the clamping bar 52 and said stem is, in turn, provided with a handle 56, the stem operates through guides 51, these located between the spaced parallel rails 58. Another bar 58 in the frame structure serves to complete the frame and to accommodate the handle 60.

The work holder 4! is bodily removable from the sustaining and guiding track devices and it will be noted in Figure 4 that these devices extend out over the chute 43 so as to facilitate handling of said work holder. In practice, the work 53 is simply clamped between the abutment rail 5| and the spring-pressed clamping bar 52, this by convenient operation of the handle means 56. Usually the block of work is placed on the table or shelf 44 so that it is bodily supported and the frame is then aligned with the shelf and the Work is clamped between said parts 5| and 52. The table serves to uniformly place the block or work in place so that one-half extends above the frame and the other half below.

The work clamped in the holder is positioned between the inner flights of the belts and the belts are set into operation to accomplish the job in an evident manner. The water as before explained is sprayed from the nozzles 32 on the belts and the belts sand the work with expediency and convenience. Of course, it is necessary to adjust the belt assemblies toward and from each other into desired spaced relation to accommodate the type of work which is placed in said holder. The holder acts somewhat like a drawer and can be conveniently slid in or slid out. When it is slid out, the job being finished, the work is deposited on the shelf 44 where it can be thereafter conveniently removed.

It is evident too, that the top belt can be used individually. That is to say, in certain hand jobs where it is desired to press the work by hand, against the belt, the work is placed in through the open top of the structure and is manipulated and maneuvered in a well known manner.

In practice, it is intended to enclose the belt However, and as a general proposition the top is left open to permit access to be had to the top belt when it is used individually.

It is thought thatpersons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after con- It is .a slid- V 4 sidering the description in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in the shape, size and arrange-- ment of details coming within the field of invention claimed may be resorted to without departing from the spirit and scope of the invention as claimed.

Having described the invention, what is claimed as new is: I 1 'f 1. In a work sander of the class described, a relatively stationary main frame having a pair of feed screws vertically mounted for rotation therein, an adjusting shaft mounted for rotation atop said frame, operating means for said shaft.

and operating connections between the ends of said shaft and said feed screws, an auxiliary substantially U-shaped frame having a longitudinal connective portion and transverse ends within the limits of the first-named main frame having means adjustably mounted on said feed screws whereby to raise and lower said U-shaped frame, drums mounted in said U-shaped frame, an endless belt trained over said drums, and a water spraying nozzle mounted in said frame to coact with one end of the belt, in the manner and for the purposes described.

2. In a work sander of the class described, arelatively stationary main frame structure, upper and lower horizontally disposed and spaced belt units, eachbelt unit comprising a frame located within the marginal limits of the aforementioned frame structure, drums mounted for rotation in said frame, and an endless sanding belt trained over the drums; a motor supporting platform projecting from one end of said frame structure and located in aplane representing an imaginary line between the upper and lower belt units, a motor shiftably mounted on said platform, and individual operating connections between the motor shaft and the respective adjacent drums of said upper and lower units, said operating connections being adjusted by the shifting of the motor on the platform.

3. In a work sander of the class described, a relatively stationary main frame structure, upper and lower horizontally disposed and spaced belt units, each belt unit comprising a frame located within the marginal limits of the aforementioned frame structure, drums mounted for rotation in said frame, and an endless sanding belt trained over the drums; a motor supporting platform probetween the upper and lower belt units, a motor,

shiftably mounted on said platform, and individual operating connectionsv between the motor shaft and the respective adjacent drums of said upper and lower units, said operating connections being adjusted by the shifting of the motor on the platform, together with a link pivotally connected at one end with the motor and pivotally connected at its opposite end with one of the adjacent drums.

4. In a work sander of the class described, a relatively stationary main frame provided with a pair of vertical feedscrews mounted for rotation, an adjusting shaft mounted for rotation atop the frame, operating means for said shaft and operating connections between the ends of said shaft and said feed screws, an auxiliary platens, and having adjustable devices at outer ends connecting same with said feed screws for raising and lowering the U-shaped frame, drums mounted in said U-shaped frame, an endless belt trained over said drums and said platens, the platens serving as backing elements for the upper and lower flights of said belt, a water spraying nozzle mounted in said main frame to coact with one end of the belt, and a water trapping and collecting receptacle mounted in said main frame beneath said U-shaped frame and belt also beneath the water spraying nozzle.

5. In a work sander of the class described, a relatively stationary main frame provided with a pair of vertical feed screws mounted for rotation, an adjusting shaft mounted for rotation atop the frame, operating means for said shaft and operating connections between the ends of said shaft and said feed screws, an auxiliary substantially U-shaped frame horizontally arranged and positioned within the limits of the first named main frame, said U-shaped frame being provided with parallel vertically spaced platens, and having adjustable devices at outer ends connecting same with said feed screws for raising and lowering the U-shaped frame, drums mounted in said U-shaped frame, an endless belt trained over said drums and said platens, the platens serving as backing elements for the upper and lower flights of said belt, a water spraying nozzle mounted in said main frame to coact with one end of the belt, and a water trapping and collecting receptacle mounted in said main frame beneath said U-shaped frame and belt also beneath the water spraying nozzle, and a work placement and removal shelf vertically and adjustably mounted within the limits of said water collecting receptacle and arranged in a position to coact with work holding means such as is adapted for disposition beneath the lower flight of the belt.

6. In a work sander of the class described, a

relatively stationary frame structure, upper and lower parallel endless sanding belts adjustably mounted in said frame structure and in superposed relationship, means for spraying water on the ends of the belt, a water collecting pan mounted in the frame beneath said sanding belt and also beneath said water spraying means, this for trapping and collecting water, a pair of hori-. zontally disposed and aligned guide tracks mounted in said frame and located between the adjacent opposed flights of said sanding belt, said guide tracks being of lengths to determine within the marginal limits of said water collecting receptacle, a clamping frame-like work holder adjustable in said guide track and movable in drawer-like fashion in and out in respect to the adjacent flights of the respective belt.

7. In a work sander of the class described, a relatively stationary frame structure, upper and lower parallel endless sanding belts adjustably mounted in said frame structure and in superposed relationship, means for spraying water on the ends of the belt, a, water collecting pan mounted in the frame beneath said sanding belt and also beneath said water spraying means, this for trapping and collecting water, a pair of horizontally disposed and aligned guide tracks mounted in said frame and located between the adjacent opposed flights of said sanding belt, said guide tracks being of lengths to determine within the marginal limits of said water collecting receptacle, a clamping frame-like work holder adjustable in said guide track and movable in drawer-like fashion in and out in respect to the adjacent flight of the respective belt, and Work placement and removal shelf means vertically and adjustably mounted within the limits of said receptacle and adapted for coaotion with said tracks, as well as said clamping frame-like Work holder.

DANIEL DOHERTY. 

